Change first valid DRM drawable ID to be 1 instead of 0.

This makes it easier for userspace to know when it needs to allocate an ID.

Also free drawable information memory when it's no longer needed.
(cherry picked from df7551ef73 commit)

linux-core/drm_drv.c

@@ -163,6 +163,18 @@ int drm_lastclose(drm_device_t * dev)
 	if (dev->irq_enabled)
 		drm_irq_uninstall(dev);
 
+	/* Free drawable information memory */
+	for (i = 0; i < dev->drw_bitfield_length / sizeof(*dev->drw_bitfield);
+	     i++) {
+		drm_drawable_info_t *info = drm_get_drawable_info(dev, i);
+
+		if (info) {
+			drm_free(info->rects, info->num_rects *
+				 sizeof(drm_clip_rect_t), DRM_MEM_BUFS);
+			drm_free(info, sizeof(*info), DRM_MEM_BUFS);
+		}
+	}
+
 	mutex_lock(&dev->struct_mutex);
 	del_timer(&dev->timer);
 

shared-core/drm_drawable.c

@@ -92,13 +92,13 @@ done:
 		bitfield[i] = 0;
 	}
 
-	draw.handle = i * 8 * sizeof(*bitfield) + j;
+	draw.handle = i * 8 * sizeof(*bitfield) + j + 1;
 	DRM_DEBUG("%d\n", draw.handle);
 
 	spin_lock_irqsave(&dev->drw_lock, irqflags);
 
 	bitfield[i] |= 1 << j;
-	info[draw.handle] = NULL;
+	info[draw.handle - 1] = NULL;
 
 	if (bitfield != dev->drw_bitfield) {
 		memcpy(bitfield, dev->drw_bitfield, dev->drw_bitfield_length *
@@ -132,7 +132,7 @@ int drm_rmdraw(DRM_IOCTL_ARGS)
 {
 	DRM_DEVICE;
 	drm_draw_t draw;
-	unsigned int idx, shift;
+	unsigned int id, idx, shift;
 	unsigned int irqflags;
 	u32 *bitfield = dev->drw_bitfield;
 	unsigned int bitfield_length = dev->drw_bitfield_length;
@@ -142,10 +142,11 @@ int drm_rmdraw(DRM_IOCTL_ARGS)
 	DRM_COPY_FROM_USER_IOCTL(draw, (drm_draw_t __user *) data,
 				 sizeof(draw));
 
-	idx = draw.handle / (8 * sizeof(*bitfield));
+	id = draw.handle - 1;
-	shift = draw.handle % (8 * sizeof(*bitfield));
+	idx = id / (8 * sizeof(*bitfield));
+	shift = id % (8 * sizeof(*bitfield));
 
-	if (idx >= bitfield_length ||
+	if (idx < 0 || idx >= bitfield_length ||
 	    !(bitfield[idx] & (1 << shift))) {
 		DRM_DEBUG("No such drawable %d\n", draw.handle);
 		return 0;
@@ -157,6 +158,12 @@ int drm_rmdraw(DRM_IOCTL_ARGS)
 
 	spin_unlock_irqrestore(&dev->drw_lock, irqflags);
 
+	if (info[id]) {
+		drm_free(info[id]->rects, info[id]->num_rects *
+			 sizeof(drm_clip_rect_t), DRM_MEM_BUFS);
+		drm_free(info[id], sizeof(**info), DRM_MEM_BUFS);
+	}
+
 	/* Can we shrink the arrays? */
 	if (idx == bitfield_length - 1) {
 		while (idx >= 0 && !bitfield[idx])
@@ -164,7 +171,7 @@ int drm_rmdraw(DRM_IOCTL_ARGS)
 
 		bitfield_length = idx + 1;
 
-		if (idx != draw.handle / (8 * sizeof(*bitfield)))
+		if (idx != id / (8 * sizeof(*bitfield)))
 			bitfield = drm_alloc(bitfield_length *
 					     sizeof(*bitfield), DRM_MEM_BUFS);
 
@@ -222,11 +229,12 @@ int drm_update_drawable_info(DRM_IOCTL_ARGS) {
 	DRM_COPY_FROM_USER_IOCTL(update, (drm_update_draw_t __user *) data,
 				 sizeof(update));
 
-	id = update.handle;
+	id = update.handle - 1;
 	idx = id / (8 * sizeof(*bitfield));
 	shift = id % (8 * sizeof(*bitfield));
 
-	if (idx >= bitfield_length || !(bitfield[idx] & (1 << shift))) {
+	if (idx < 0 || idx >= bitfield_length ||
+	    !(bitfield[idx] & (1 << shift))) {
 		DRM_ERROR("No such drawable %d\n", update.handle);
 		return DRM_ERR(EINVAL);
 	}
@@ -304,10 +312,13 @@ error:
  */
 drm_drawable_info_t *drm_get_drawable_info(drm_device_t *dev, drm_drawable_t id) {
 	u32 *bitfield = dev->drw_bitfield;
-	unsigned int idx = id / (8 * sizeof(*bitfield));
+	unsigned int idx, shift;
-	unsigned int shift = id % (8 * sizeof(*bitfield));
 
-	if (idx >= dev->drw_bitfield_length ||
+	id--;
+	idx = id / (8 * sizeof(*bitfield));
+	shift = id % (8 * sizeof(*bitfield));
+
+	if (idx < 0 || idx >= dev->drw_bitfield_length ||
 	    !(bitfield[idx] & (1 << shift))) {
 		DRM_DEBUG("No such drawable %d\n", id);
 		return NULL;